On a windy Friday morning last month, three men stood on Red Hill by the southern shore of the Salton Sea, admiring the geothermal power plants belching steam in the distance. The hill was once an island, but the water has long since receded, leaving a 100-foot-high pile of mud. The men had come from Australia to stand on that desolate hill. They weren't there for the mud, though, or for the water.

Charles Davis' Hell's Kitchen restaurant on Mullet Island, by the southern shore of the Salton Sea, in the early 1900s(Photo: Courtesy of Salton Sea History Museum)

Rod Colwell pointed northeast along the shoreline toward Mullet Island, a small outcropping jutting into the water. Like Red Hill, it isn't actually an island anymore, and like Red Hill, it's considered an active volcano, although they've both been dormant for at least 2,000 years. There used to be a restaurant and dance hall on Mullet Island, built by the pioneer Charles Davis in 1908, just after the Colorado River broke through an irrigation canal and created the accidental lake known as the Salton Sea. Today only ruins remain — concrete foundations, a few toilets — but the outcropping is still named for the mullet fish Davis famously served at his restaurant.

Colwell plans to build a massive geothermal power plant nearby, and to name it after that restaurant: Hell's Kitchen.

The name might be more appropriate now than it was in 1908: The land is hot, empty and getting filthier by the year as the Salton Sea shrinks, which has allowed gusting winds to kick up dust from the exposed lakebed. Fish carcasses line the increasingly salty lake, giving the area a rotten-egg stench. Beneath the parched landscape, though, lies a reservoir of mineral-rich water, heated to temperatures as high as 700 degrees Fahrenheit by the Earth's natural heat. The same geologic forces that make California so earthquake-prone allow that heat to rise near the surface, creating what experts say is the world's most powerful geothermal energy hot spot.

Left to right: Controlled Thermal Resources executives Rod Colwell, Paul Horsburgh and Jason Czapla stand on Red Hill by the southern shore of the Salton Sea on April 29, 2016.(Photo: Robert Hopwood/The Desert Sun)

Colwell wants to tap into that resource. He's come all the way from Brisbane, Australia to do it.

"We looked at the Geysers, we looked at Lassen County," Colwell said as he drove down a dirt road toward Red Hill earlier that morning, referring to geothermal hot spots in Northern California. "And then we were looking at the Salton Sea at the same time. And the Salton Sea had basically come up trumps. It was just a far better resource."

There are already 11 geothermal plants by the southern shore of California's largest lake, churning out clean, climate-friendly electricity almost every hour of every day. But despite the area's vast untapped potential, only one new power plant has opened since 2000. Geothermal has its virtues, but building a plant can cost hundreds of millions of dollars. Those high up-front costs have largely scared away investors.

Colwell's company, Controlled Thermal Resources, think it's solved the cost puzzle. By building Hell's Kitchen five time bigger than any of the other geothermal facilities in the area — 250 megawatts instead of 50 — executives believe they can reap major savings through economies of scale. That would allow the company to sell the electricity at a relatively low price, which in turn could make a bank more likely to offer a loan.

It's hard to know whether Controlled Thermal will succeed where other companies have failed. But CEO Colwell and his lieutenants are confident. They've made dozens of trips to the Imperial Valley over the last four years, and in March they leased 1,880 acres from the Imperial Irrigation District, which owns the land where their project would be built. This month their chief engineer, Jason Czapla, will move from Australia to El Centro, south of the lake, to oversee operations. The company plans to drill exploratory wells this fall, to start construction by 2018 and to open the plant by 2020.

Controlled Thermal has reason to be confident: California is speeding toward a clean-energy future. The state has gotten to 25 percent renewable energy mostly though solar and wind, but the sun doesn't shine all day, and the wind doesn't always blow. A growing number of experts think more geothermal is key to helping the state meet its 50 percent clean energy mandate, which Gov. Jerry Brown signed into law last year.

"This will happen. When the drill rig comes, you guys can come down again and crawl over it. We’ll have beers and barbecue," Colwell said. "But the thing is, it is happening."

EnergySource's Featherstone geothermal power plant is framed by bubbling mud pots near the southern shore of the Salton Sea on April 29, 2016.

(Photo: Robert Hopwood/The Desert Sun)

High cost, high reward

Local officials see geothermal development as a potential economic boon for the Imperial Valley, a poor, largely agricultural corner of California. Imperial County's unemployment rate was 18.6 percent in March, the second-highest number in the state, and its median income was less than $42,000, according to the U.S. Census Bureau. Controlled Thermal says it would employ about 280 people during construction and 85 full-time operations staff once Hell's Kitchen is built. Paul Horsburgh, the company's executive director, said he and Colwell plan to "employ as many people from the valley as possible."

Czapla, the company's chief engineer, "will be working closely with the tech colleges and schools because this resource is unique," Colwell said. "It needs specialists you can't get from anywhere else. We need to train, and we need to do it soon."

Imperial Valley residents have heard such promises before. A few years ago, a startup called Simbol Materials wowed the region with plans to build a high-tech facility to extract lithium from geothermal brine, saying it would employ 400 people during construction and as many as 150 permanently. But the company was unable to secure financing and folded last year, after firing dozens of employees from its demonstration plant.

Plans to build more geothermal plants have failed to materialize, too. CalEnergy — which is owned by Warren Buffett's Berkshire Hathaway Energy, and which operates 10 of the 11 geothermal plants by the Salton Sea — has been trying for years to obtain financing for new projects, to no avail. In 2014, the California Energy Commission gave the company its third extension to start construction on the 159-megawatt Black Rock geothermal plant, which the commission originally approved in 2003. CalEnergy was supposed to start construction by 2008, then by 2011, then by 2014. Now it has until 2019

It hasn't been impossible to build: Another company, EnergySource, opened the 49.9-megawatt Featherstone plant in 2012. But the price tag was high: $400 million.

Colwell and his team think they've figured out how to slash construction costs. Previously, developers have built geothermal plants smaller than 50 megawatts, so as to avoid the California Energy Commission's potentially arduous permitting process. (They've still needed to get approval from Imperial County.) By building at 250 megawatts, Controlled Thermal expects to reap huge savings. The company also hopes to capitalize on the downturn in the oil and gas sector.

"There are so many rigs that are just sitting around doing nothing because of oil and gas. The timing’s perfect," Colwell said. "That's why we're pushing to get our drilling out of the way. It's probably half the price of what it was, say, four years ago."

The California Public Utilities Commission estimates the up-front costs of building a geothermal plant at $6.6 million per megawatt. For a 250-megawatt plant — like the one Controlled Thermal plans to build — that would add up to $1.65 billion. But the company thinks it can build Hell's Kitchen for less than $850 million.

Colwell, Horsburgh and Czapla have never built a geothermal plant, so they know onlookers are skeptical. Czapla got his doctorate in geothermal engineering from the University of Queensland in Australia, but Horsburgh's background is in real estate. Colwell has worked mostly in commercial property development; renewable energy caught his interest after he worked on a rooftop solar project at a previous company.

To make up for their inexperience, Controlled Thermal's executives hired a stable of local consultants with deep histories at the Salton Sea. Among them is Dennis Kaspereit, who spent 10 years as CalEnergy's director of geothermal resources and now works at the Geothermal Resource Group, a Palm Desert-based consultant. Kaspereit is working closely with Controlled Thermal, and he thinks the company will succeed.

"The team that they're putting together is going to be people with hundreds of years of experience (at the Salton Sea). And I've seen how their approach on getting the contracts and the financing is just solid," he said. "I can't discuss those, but I've seen them, and I know that they will get it done. And part of it's just passion and drive."

Karl Gawell, executive director of the Geothermal Energy Association, an industry trade group, said he's heard "plenty of critiques" of Controlled Thermal, including questions about the company's lack of experience and the technology it's using. While he said he doesn't want to "get into a shouting match" between geothermal companies, he thinks building a bigger plant to reduce costs is a sound strategy.

“I’m trying to give them the benefit of the doubt," Gawell said. "There are a lot of people who say you can't do something. My hope is they succeed."

Controlled Thermal Resources has leased this land near the southern shore of the Salton Sea, seen on April 29, 2016.

(Photo: Robert Hopwood/The Desert Sun)

Untapped potential

Geothermal technology is relatively simple. Developers drill into underground rock formations filled with cracks and extremely hot water. At the Salton Sea, the fluid is actually brine — 75 percent water and 25 percent minerals, mostly chloride and sodium — and there are plenty of cracks in the rock, thanks to the San Andreas Fault. Those cracks allow the Earth's heat to get close to the surface, heating the brine to high temperatures.

After drilling the wells, power plant operators pump the super-heated brine through a series of pipes, methodically lowering the pressure on the fluid to create steam, which is used to turn turbines and generate electricity. Eventually the brine starts to cool down, and the water and condensed steam are re-injected into the underground reservoir. It's a renewable process that doesn't emit planet-warming greenhouse gases.

EnergySource's Featherstone plant brought the Salton Sea's existing geothermal capacity to nearly 400 megawatts, enough to power more than 400,000 average California homes. But the bulk of the area's potential is still untapped. In a 2002 paper, Kaspereit estimated that potential at 2,230 megawatts. He's currently finalizing an updated version of the paper, which pegs the potential at 2,950 megawatts.

Controlled Thermal owns the rights to a lot of that energy. The company estimates that its 1,880-acre lease will produce close to 400 megawatts of geothermal power, with another 400 megawatts underlying an additional 2,200 acres to which Controlled Thermal has a "right of first refusal" from the Imperial Irrigation District.

Geothermal supporters say it's time to develop that energy. California is installing more solar panels than ever, but some experts say the state will need more geothermal if it wants to meet its 50 percent clean energy mandate. That's because unlike geothermal plants, solar farms and wind turbines don't produce electricity around the clock.

So far that hasn't been a problem, but some experts fear it will be in the long run. Building too many solar farms and rooftop solar systems could be especially problematic because the sun only shines during the day, and electricity demand tends to peak in the evening, when people get home from work.

"Geothermal could be and should be a very big player with respect to California meeting its goals," said Bill Glassley, a geology professor at UC Davis and director of the California Geothermal Energy Collaborative, a research group that supports the industry. "Now is the time to be looking at new geothermal."

Geothermal advocates say solar farms aren't practical without natural gas-fired power plants, which pick up the slack when the sun isn't shining. Those gas plants spew greenhouse gases into the atmosphere, and they're relatively expensive to build and operate. A report last month from a clean-energy trade group and the National Renewable Energy Laboratory found that using Salton Sea geothermal to help meet the state's 50 percent mandate could save energy consumers several hundred million dollars per year by 2030, largely by reducing the need for gas plants.

"When you want 100 megawatts of solar, what you're saying is you want a 100-megawatt solar plant and a 100-megawatt gas plant. That's the real truth of the matter," Kaspereit said.

The moon shines over a solar plant near the southern end of the Salton Sea, in California's Imperial Valley, on Nov. 23, 2015.(Photo: Jay Calderon/The Desert Sun)

Solar supporters say that criticism is unfair. While gas plants have been used to complement solar farms so far, state officials and private companies are developing new strategies to accommodate more solar. Some of those strategies involve encouraging homes and businesses to change their energy habits, so that demand better aligns with supply. When supply still exceeds demand, solar energy could be stored in batteries, or used to charge electric vehicles. California could also share more electricity with its neighboring states, making it easier to balance supply and demand.

Shannon Eddy, executive director of the Large-scale Solar Association, a California trade group, said it's a "fundamental misperception" to assume solar power will always rely on gas plants.

"It’s too easy a conclusion to jump to, to say we need gas to shore up solar or wind," she said. "Not only can you integrate high levels of renewable energy into the grid in California, you can do it without gas."

Still, Eddy believes we can't have too much clean energy. Considering the dangers posed by climate change, she said, "We need to get to 100 percent renewables as fast as we possibly can."

"Now's certainly the time to start looking at all the ways to start bringing renewable energy online — more solar, more wind, more geothermal, more biomass," Eddy said.

Mud bubbles out of the ground as EnergySource's Featherstone geothermal power plant belches steam in the distance on April 29, 2016.

(Photo: Robert Hopwood/The Desert Sun)

The Salton Sea

Imperial Valley officials have long argued that new geothermal development could help fund restoration projects at the Salton Sea, which has been shrinking as its only significant water source — farm runoff — decreases. The lake was created by human error, but it now serves as critical habitat for fish and migrating birds, and its continued decline could unleash lung-damaging air pollution across the Imperial and Coachella valleys.

Under the terms of its lease agreement, Controlled Thermal would pay the Imperial Irrigation District royalties of between 3 and 4 percent on any electricity or minerals it sells. It's not clear how much of that money, if any, the district would allocate to Salton Sea projects. Local officials have at times floated the idea of charging energy developers a special fee for Salton Sea restoration, but a skeptical report from the National Renewable Energy Laboratory found last year that such a fee would probably make geothermal development impossible, since building the plants is already so expensive.

The inside of Charles Davis' Hell's Kitchen restaurant on Mullet Island, at the Salton Sea.(Photo: Courtesy of Salton Sea History Museum)

If Controlled Thermal drills its exploratory wells as planned later this year, it will actually mark the return of geothermal to the Mullet Island area after nearly a century. Having noticed the burbling mud pots nearby — a telltale sign of the hot brine lurking beneath the surface — a power company drilled three test wells on the island in 1927, Kaspereit said. The company didn't drill deep enough, though, and eventually it gave up.

Czapla will be spending a lot of time in the area after he moves to El Centro later this month. He grew up in Oregon before working overseas and studying in Australia, but in some ways he already feels local.

"It's funny, coming here," he said last month as he walked up Red Hill. "My dad's from Long Beach, and he grew up water-skiing around Mullet Island where we have the lease. So I've come full circle."

Sammy Roth writes about energy and the environment for The Desert Sun. He can be reached at sammy.roth@desertsun.com, (760) 778-4622 and @Sammy_Roth.

Controlled Thermal Resources has leased this land near the southern shore of the Salton Sea, seen on April 29, 2016.